How do i do a problem like 3/27 + 5/9 =​

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

Me. i can't figure out this question. give an explanation too. .

William invested $5000 in an account that earns 3.8% interest, compounded annually. the formula for compound interest is a(t) = p(1 + i)t. how much did william have in the account after 6 years? (apex)